Fluoromethyl-1,1,1,3,3,3-hexafluoroisopropyl ether, as described in U.S. Pat. Nos. 3,689,571 and 3,683,092, is an anesthetic which is showing very promising results in clinical trial, being non-inflammable under conditions of use, and having advantages that appear to greatly outweigh any minor disadvantages.
For clinical use, it is necessary of course to produce the above ether material in large quantities, for example, by a synthesis technique as described in the above patents, and the abandoned original application, Ser. No. 771,365, filed Oct. 28, 1978, from which the above-cited U.S. patents claim priority.
Another currently preferred synthesis technique under consideration is the improvement as described in the patent application of Robert L. Simon et al., filed simultaneously with this present application and entitled "Method of Synthesizing Fluoromethylhexafluoroisopropyl Ether" now U.S. Pat. No. 4,250,334.
In many of these synthesis techniques, the corresponding alcohol, for example, 1,1,1,3,3,3-hexafluoroisopropanol, is a reactant. Such material is currently very expensive, largely because the various byproducts produced with the material in the presently used commercial synthesis routes and difficult to separate from the acetone precursor of the alcohol product.
In accordance with this invention, synthesis techniques are provided in which impure hexafluoroacetone mixtures may be utilized as starting material, resulting in great cost savings, since the final expensive purification steps normally utilized in the commercial hexafluoroacetone reactant are rendered unnecessary.
In one instance, the resulting alcohol product is easily separable by simple distillation from its impurities, while in another case, the original impurity is also more easily separable, but may be utilized as a reactant for the desired further step of synthesis of the hexafluoroisopropyl alcohol into the corresponding fluoromethyl ether.